This application claims priority from Korean Patent Application No. 2002-76217, filed on Dec. 3, 2002, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present invention relates to a method and apparatus for representing a gradation on a display device which displays a picture by sequentially executing an address period and a sustain period, such as, a plasma display panel (PDP).
2. Description of the Related Art
A known PDP electrode driving method is disclosed in U.S. Pat. No. 5,541,618. A conventional panel driving method has three timing period, including a reset (initialization) period, an address (write) period, and a sustain (display) period. During the reset period, each cell is initialized so that an addressing operation can be properly performed on each cell. During the address period, wall charges are accumulated on the cells which are to be lit in a panel. During the sustain period, a discharge for picture display takes place on the addressed cells.
The above U.S. Patent discloses a method of driving a PDP by separately executing over time an address period and a sustain period in order to represent a gradation in a frame-subfield structure. A sustain operation is executed concurrently on all pixels after all scan electrodes are completely addressed. According to this driving method, a sustain discharge operation of a certain scan line is not performed until the last scan line finishes an addressing operation.
Therefore, in the known method for representing a gradation, a significant time gap exists from an addressing operation to a sustain discharge operation on the addressed cell. This may cause an unstable sustain discharge operation.